JP3625300B2 - Image forming apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an image forming apparatus applied as, for example, an electronic copying machine.
[0002]
[Prior art]
When an image is formed by an electronic copying machine, an operator manually sets a document on the document table or sets an original on the document table by an automatic document feeder to form an image.
[0003]
During this image formation, for example, the document feeding by the automatic document feeding device may be in a defective state, or the key counter may be dropped during the copying operation using the key counter. .
[0004]
In such a case, the electrostatic latent image on the photosensitive drum is forcibly erased by cutting the charge on the photosensitive drum or turning on the erasing LED array to remove the charge from the photosensitive drum. The copying operation is interrupted, and the fed paper is discharged as white paper.
[0005]
[Problems to be solved by the invention]
However, conventionally, when a blank sheet is discharged, it is discharged as a simple copy error.
[0006]
For this reason, when the discharged white paper is reused, it is necessary for the user to return the white paper to the paper feed cassette, and there is a disadvantage that the resource reuse efficiency is poor.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can be automatically reused without a user's hand when blank paper is generated.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an image carrier that carries an image, an image forming unit that forms an image on the image carrier, and the image carrier that is formed by the image forming unit. A transfer means for transferring the image on the body to the paper, a paper feed means for supplying paper of a different size to an image transfer portion between the transfer means and the image carrier, and the image is transferred by the transfer means. A paper discharge tray that receives the discharged image-transferred paper, a stacking unit that stacks sheets that pass through the image transfer unit in a blank state, and a sheet that is stacked on the stacking unit is supplied to the image transfer unit. When paper sheets are already stacked on the stacking unit when stacking blank sheets on the stacking unit, if the size of the sheet to be stacked and the size of the stacked sheets are the same size, the stacking unit Different sizes Comprising and control means to discharge onto the discharge tray.
[0016]
【Example】
Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings.
[0017]
FIG. 2 is an external view showing the overall configuration of the electronic copying apparatus, and FIG. 3 is an internal configuration diagram thereof. In the figure, reference numeral 1 denotes an apparatus main body. A document placing table 2 is provided on the upper surface of the apparatus main body 1, and an automatic document feeder 2 A for conveying the document onto the document placing table 2 is provided on the document placing table 2. Is provided.
[0018]
A scanner unit 5 is provided on the upper side in the apparatus main body 1. The scanner unit 5 includes first and second carriages 6 and 7 that are movable. An exposure lamp 8 and a first reflection mirror 9 are disposed on the first carriage 6. Second and third reflecting mirrors 10 and 11 are disposed on the second carriage 7. An optical lens 13 and a light receiving element 14 are disposed in the optical path of the reflected light reflected by the third reflecting mirror 11.
[0019]
A paper transport path 15 is provided in a horizontal state below the scanner unit 5. A registration roller 22, an image forming unit 17, a conveyance belt 27, a fixing unit 18, a feed roller 28, a gate 19, and a discharge roller 20 are sequentially disposed in the sheet conveyance path 15 along the sheet conveyance direction. Yes.
[0020]
The image forming means 17 is provided with a photosensitive drum 31 as an image bearing member so as to be rotatable. A charging charger 32 and an erasing LED array are sequentially provided as charging means around the photosensitive drum 31 along the rotating direction. 37, an exposure unit 33, a developing device 34, a transfer and peeling chargers 35a and 35b, and a cleaner 36 are disposed.
[0021]
A polygon mirror 39 scans information light. Light scanned by the polygon mirror 39 is sent to the exposure unit 33 via the optical system 40.
[0022]
The developing device 34 is rotatably provided with a developing roller 62 that contains a two-component developer composed of toner and a carrier and supplies the developer.
[0023]
The fixing unit 18 includes a heat roller 41 and a press roller 42 that is in rolling contact with the heat roller 41.
[0024]
Further, as shown in FIG. 1, the lower part of the paper conveyance path 15 is provided with upper and lower conveyance path parts 29A and 29B for conveying the paper during double-sided copying. The conveyance path parts 29A and 29B include A plurality of pairs of transport rollers 30 are disposed along the paper transport direction. Further, stack portions 45A and 45B as upper and lower stacking means for stacking sheets discharged from the transport path portions 29A and 29B are provided below the upper and lower transport path portions 29A and 29B, respectively. . The sheet conveyed by the sheet conveying path 15 is selectively guided to the discharge tray 4 side or the upper and lower conveying path parts 29A and 29B side by the rotation of the gate 19. Further, the paper guided to the upper and lower transport path portions 29A and 29B by the rotation of the gate 19 is selectively guided to the upper or lower transport path portions 29A and 29B by the rotation of the gate 66. It has become so. The sheets stacked in the stack sections 45A and 45B are taken out by a pickup roller 46 constituting a re-feeding unit, and are fed one by one to the image transfer section 17a by a paper feed roller 47.
[0025]
A plurality of paper feed cassettes 3A, 3B, 3C serving as paper feeding means are arranged in the vertical direction in the lower part of the apparatus main body 1. The paper in the paper feed cassettes 3A, 3B, 3C is taken out by the pickup roller 23, and the taken out paper is separated one by one by the paper feed roller 24 and the separation roller 25 and sent to the vertical conveyance path 55. It is supposed to be. In the vertical conveyance path 55, aligning roller pairs 16 are arranged corresponding to the respective paper feed cassettes 3A, 3B, 3C.
[0026]
On the other hand, a manual paper feed unit 51 and a large-capacity paper feed unit 52 are arranged vertically on one side of the apparatus main body 1. The sheets of the manual sheet feeding unit 51 and the large-capacity sheet feeding unit 52 are supplied to the registration rollers 22 of the conveying path 15 by sheet feeding rollers 53 and 54.
[0027]
Further, on the other side of the apparatus main body 1, a paper discharge tray 4 for receiving the image-formed paper discharged from the paper discharge roller 20 is provided.
[0028]
Incidentally, the automatic document feeder 2A is provided with a sensor (not shown), and when the document fed from the automatic document feeder 2A is jammed, the sensor detects the document. The detection signal of the sensor is sent to the control unit 61 shown in FIG. When the control unit 61 receives the detection signal, the control unit 61 stops the sheet feeding operation of the sheet feeding cassettes 3A to 3D, the manual sheet feeding unit 51, or the large capacity sheet feeding unit 52, and the sheet feeding has already been performed. In this case, the charging charger 32 of the image forming means 17 is turned off, and all the erasing LED arrays 37 are turned on.
[0029]
Further, the control unit 61 determines whether or not the image has already been formed on the photosensitive drum 31. If the image has been formed, the controller 61 guides to the discharge tray 4 side through the gate 19, and if the image has not been formed, the gate 19 is turned on. And is guided to the lower gate 66 side.
[0030]
Further, the control unit 61 operates the gate 66 to selectively guide the paper to the upper transport path 29A or the lower transport path 29B.
[0031]
The upper and lower stack portions 45A and 45B are provided with a sensor (not shown) for detecting the accumulation of blank paper, and when this sensor (not shown) detects that no blank paper is accumulated. The determination based on the size of the white paper to be stacked is unnecessary, and stacking is performed with priority over the upper stack portion 45A.
[0032]
Further, when blank paper has been accumulated in either of the upper and lower stack portions 45A and 45B, the size of the paper to be accumulated and the size of the accumulated white paper are determined. If the size is different, blank paper is newly accumulated on the unstacked stack portion, and the size and the number of accumulated sheets are automatically stored.
[0033]
Further, when both the upper and lower stack portions 45A and 45B have already accumulated the blank paper, the size of the paper to be accumulated and the size of the accumulated white paper are discriminated, and the blank paper is accumulated in the stack portion of the same size. .
[0034]
If both the upper and lower stack portions 45A and 45B have the same size, the upper stack portion 45A is preferentially selected, and the upper and lower stacks 45A and 45B have different sizes. The paper is discharged to the paper discharge tray 4.
[0035]
Further, even if there are stack portions of the same size, if the number of stacked sheets exceeds an arbitrary stacking upper limit number, the sheets are discharged to the sheet discharge tray 4.
[0036]
Further, when the same size as the paper size existing in the stack units 45A and 45B for stacking blank paper is selected in the next copying operation, the control unit 61 starts from the stack units 45A and 45B for stacking blank paper. Feed paper with priority.
[0037]
FIG. 4 shows a display panel 70 provided in the display panel unit 69 of FIG.
[0038]
This display panel 70 shows the presence / absence of sheets in the stack sections 45A and 45B and a display for stacking selection. In the figure, reference numeral 71 denotes a display unit for displaying the paper size in the selected stack unit 45A (45B), and 72 denotes a cassette switching key. The cassette switching key 72 switches between paper feeding from the paper feeding cassettes 3a to 3C and paper feeding from the stack unit 45A (45B). Reference numerals 73 and 74 denote selection keys for selecting the stack unit 45A (45B). Reference numerals 75 and 76 indicate whether or not there is a sheet in the stack 45A (45B), and light up when a blank sheet exists.
[0039]
Thus, at the time of image formation, a document is set on the automatic document feeder 2A and the copy button 69 is turned on. As a result, the document is sent and set on the document table 2, the exposure lamp 8 is turned on, and the first and second carriages 6 and 7 are moved. Thereby, the original is scanned with light, and the reflected light reflected from the original by this scanning is received by the light receiving element 14 via the first to third reflecting mirrors 9 to 11 and the optical lens 13 to read the image. The read image is sent to the polygon mirror 39 as information light via a transmission system (not shown). The information light sent to the polygon mirror 39 is scanned by the rotation of the polygon mirror 39 and applied to the photosensitive drum 31 through the optical system 40. The surface of the photosensitive drum 31 is uniformly charged by the charging charger 32, and an electrostatic latent image of the original is formed. The electrostatic latent image is sent to the developing device 34 by the rotation of the photosensitive drum 31 and supplied with toner to be visualized.
[0040]
On the other hand, at this time, paper is supplied from the paper feed cassettes 3 </ b> A to 3 </ b> C, the large-capacity paper feed unit 52, or the manual paper feed unit 51. This sheet is aligned by the aligning roller 22, and then sent to the image transfer unit 17a between the photosensitive drum 31 and the transfer charger 35a, and the visible image on the photosensitive drum 31 is transferred to the sheet. The sheet on which the visible image is transferred is peeled off from the photosensitive drum 31 by the action of the peeling charger 35b, and is sent between the heat roller 41 and the press roller 42 of the fixing unit 18 by the traveling of the conveying belt 27 to be heated and heated. Pressurized and fixed. The paper on which the image is fixed is discharged to the paper discharge tray 4 via the feed roller 28, the gate 19, and the paper discharge roller 20.
[0041]
Further, during double-sided copying, the sheet is guided to the lower gate 66 by the rotation of the gate 19 and is accumulated in the stack portion 45A (45B) via the gate 66. The accumulated paper is taken out by the pickup roller 46 and the paper feed roller 47, and then conveyed by the vertical conveyance path 55, and sent to the image transfer unit 17a in an inverted state to transfer the image. The sheet on which the image has been transferred is conveyed to the fixing device 18 by the belt 27 and fixed, and then discharged to the discharge tray 4 through the gate 19.
[0042]
By the way, during the above-described image forming operation, the document fed from the automatic document feeder 2A may be jammed, resulting in document feeding failure as shown in FIG. In this case, a new paper feeding operation is stopped by the control unit 61. However, if the paper has already been fed before the paper feeding is stopped, the charging charger 32 for image formation is used. While the output is stopped, the erase LED array 37 is all turned on, and the charge on the photosensitive drum 31 is removed. As a result, the sheet sent to the image transfer portion 17a between the photosensitive drum 31 and the transfer charger 35a is transported in a blank state without transferring the image, and is sent to the lower gate 66 through the gate 19. . The blank paper is selectively guided to the upper transport path 29A or the lower transport path 29B by the rotation of the gate 66, and is accumulated in the upper or lower stack section 45A or 45B.
[0043]
During this stacking, if no blank paper is stacked on either the upper or lower stack portion 45A or 45B, the stack is preferentially stacked on the upper stack 45A regardless of the paper size.
[0044]
Also, if blank paper has been accumulated in either the upper or lower stack portion 45A, 45B, the size of the paper to be accumulated and the size of the accumulated white paper are discriminated. If the size is different, blank paper is newly accumulated on the unstacked stack portion, and the size and the number of accumulated sheets are automatically stored.
[0045]
If both the upper and lower stack portions 45A and 45B have already stored the blank paper, the paper size desired to be stacked and the accumulated blank paper size are determined, and the blank paper is stacked on the stack portion of the same size.
[0046]
Further, when both the upper and lower stack portions 45A and 45B have the same size, the upper stack portion 45A is selected with priority, and when both the upper and lower stack portions 45A and 45 have different sizes, the paper discharge tray Drain to 4.
[0047]
In addition, even if stacks of the same size exist, if the number of stacked sheets exceeds an arbitrary stacking upper limit number, the sheets are discharged to the sheet discharge tray 4.
[0048]
As described above, the blank paper accumulated in the stack unit 45A (45B) is taken out by the rotation of the pickup roller 46 and the paper feed roller 47, sent to the image transfer unit 17a, and reused.
[0049]
Therefore, the user can automatically feed and use the blank paper without having to set the blank paper again, thereby improving the resource reuse efficiency.
[0050]
In the next copying operation, when the same size as the paper size existing in the stack unit 45A (45B) is selected, the paper is preferentially fed from the stack unit 45A (45B).
[0051]
Further, when a document fed from the automatic document feeder 2A is jammed and a new sheet feeding operation is stopped, an image is already formed on the photosensitive drum 31, and this image is a part of the sheet. In this case, the sheet is discharged to the discharge tray 4 through the gate 19.
[0052]
In the case of an apparatus provided with a key counter, even when the key counter is removed, the same control as that in the above-described automatic document feeder defective sheet feeding portion is performed.
[0053]
【The invention's effect】
As described above, in the present invention, when blank paper is generated during the image forming operation, the blank paper is accumulated in the stack unit, and then the blank paper in the stack unit is re-supplied to the image transfer unit. It can be reused without bothering the user, and the resource reuse efficiency can be improved.
[0054]
Further, since the stack unit for stacking blank paper and the stack unit for double-sided image formation are used together, the configuration can be simplified and the cost can be reduced.
[0055]
Further, when the image is transferred to a part of the sheet, the sheet is discharged without being stacked on the stack unit, so that the sheet on which the image has been transferred is not reused by mistake.
[0056]
In addition, when blank sheets are stacked in the stack section, the blank sheets in the stack section are reused in preference to the sheet feeding means, so that the number of sheet replenishment times for the sheet feeding means can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a stack unit of blank paper according to an embodiment of the present invention.
FIG. 2 is an external perspective view showing an electrophotographic apparatus including the stack unit shown in FIG.
FIG. 3 is a configuration diagram showing the inside of the electrophotographic apparatus of FIG. 2;
4 is a plan view showing a part of a display panel unit of the electrophotographic apparatus of FIG. 2. FIG.
FIG. 5 is a flowchart showing the operation of the electrophotographic apparatus of FIG.
[Explanation of symbols]
3A to 3C: Paper feeding cassette (paper feeding means), 17 ... Image forming means, 17a ... Image transfer section, 31 ... Photosensitive drum (image carrier), 35a ... Transfer charger (transfer means), 45A, 45B ... Stack Part (stacking means), 46... Pickup roller (refeeding means), 48.

Claims (4)

An image carrier for carrying an image;
An image forming means for forming an image on the image carrier;
Transfer means for transferring an image on the image carrier formed by the image forming means to paper;
A paper feed means for supplying paper of different sizes to an image transfer portion between the transfer means and the image carrier;
A paper discharge tray for receiving the image-transferred paper on which the image is transferred and discharged by the transfer means;
Stacking means for stacking sheets passing through the image transfer unit in a blank state;
A paper refeeding unit for supplying the paper accumulated in the stacking unit to the image transfer unit;
When paper sheets are already stacked on the stacking unit when stacking blank sheets on the stacking unit, if the size of the sheet to be stacked and the size of the stacked sheets are the same size, they are stacked on the stacking unit and are different. If the size, control means to discharge to the output tray,
An image forming apparatus comprising: A display for displaying the size of the paper in the stacking means;
An operation unit for switching between sheet feeding from the sheet feeding unit and sheet feeding from the stacking unit;
The image forming apparatus according to claim 1, further comprising: Means for storing the size of the sheets to be stacked when the sheets are stacked on the unstacked stacking means;
The image forming apparatus according to claim 1, further comprising: The paper to be stacked is discharged to the paper discharge tray when the number of stacked sheets exceeds an arbitrary upper limit number of stacked sheets even if the size of the sheets to be stacked and the size of the stacked sheets are the same. Item 2. The image forming apparatus according to Item 1.

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